Rough out hardware differences.

platformio.ini

@@ -8,7 +8,10 @@
 ; Please visit documentation for the other options and examples
 ; https://docs.platformio.org/page/projectconf.html
 
+[platformio]
+
 [env:metro]
+build_flags = -D ARDUINO1
 platform = atmelavr
 board = metro
 framework = arduino
@@ -17,3 +20,16 @@ lib_deps =
 	paulstoffregen/Encoder@^1.4.4
 	adafruit/Adafruit GFX Library@^1.11.9
 	adafruit/Adafruit SSD1306@^2.5.9
+
+[env:esp32doit-devkit-v1]
+build_flags = -D ESP32DOIT
+platform = espressif32
+board = esp32doit-devkit-v1
+framework = arduino
+upload_speed = 921600
+monitor_speed = 115200
+lib_deps = 
+	etherkit/Etherkit Si5351@^2.1.4
+	adafruit/Adafruit GFX Library@^1.11.9
+	adafruit/Adafruit SSD1306@^2.5.9
+	igorantolic/Ai Esp32 Rotary Encoder@^1.6

src/main.cpp

@@ -13,6 +13,23 @@
 
 //User  preferences
 //------------------------------------------------------------------------------------------------------------
+#ifdef ESP32DOIT //use the ESP32 DEVKIT DOIT environment
+#pragma "ESP32DOIT" //show in console on build
+#define board      1    //Define board
+#define  IF         0       //Enter your IF frequency, ex: 455 = 455kHz, 10700 = 10.7MHz,  0 = to direct convert receiver or RF generator, + will add and - will subtract IF  offfset.
+#define BAND_INIT  7         //Enter your initial Band (1-21) at startup,  ex: 1 = Freq Generator, 2 = 800kHz (MW), 7 = 7.2MHz (40m), 11 = 14.1MHz (20m). 
+#define XT_CAL_F   33000     //Si5351 calibration factor, adjust to get exatcly 10MHz. Increasing  this value will decreases the frequency and vice versa.
+#define S_GAIN     303       //Adjust the sensitivity of Signal Meter A/D input: 101 = 500mv; 202 = 1v;  303 = 1.5v; 404 = 2v; 505 = 2.5v; 1010 = 5v (max).
+#define tunestep   32        //The  pin used by tune step push button.
+#define band       33        //The pin used  by band selector push button.
+#define rx_tx      5        //The pin used by  RX / TX selector switch, RX = switch open, TX = switch closed to GND. When in TX,  the IF value is not considered.
+#define adc        4        //The pin used by  Signal Meter A/D input.
+#define rotary1    34         //First pin for rotary encoder.
+#define rotary2    35         //Second pin for rotary encoder.
+
+#else // use the ARDUINO1 environment
+#pragma "ARDUINO1" //show in console on build
+#define board      0  //Define board
 #define  IF         0       //Enter your IF frequency, ex: 455 = 455kHz, 10700 = 10.7MHz,  0 = to direct convert receiver or RF generator, + will add and - will subtract IF  offfset.
 #define BAND_INIT  7         //Enter your initial Band (1-21) at startup,  ex: 1 = Freq Generator, 2 = 800kHz (MW), 7 = 7.2MHz (40m), 11 = 14.1MHz (20m). 
 #define XT_CAL_F   33000     //Si5351 calibration factor, adjust to get exatcly 10MHz. Increasing  this value will decreases the frequency and vice versa.
@@ -23,6 +40,8 @@
 #define adc        A3        //The pin used by  Signal Meter A/D input.
 #define rotary1    2         //First pin for rotary encoder.
 #define rotary2    3         //Second pin for rotary encoder.
+
+#endif
 //------------------------------------------------------------------------------------------------------------
 
 Rotary  r = Rotary(rotary1, rotary2);
@@ -56,11 +75,15 @@ void set_frequency(short dir)  {
   }
 }
 
+#ifdef ESP32DOIT //use the ESP32 DEVKIT DOIT environment
+  //TODO
+#else
   ISR(PCINT2_vect) {
     char  result = r.process();
     if (result == DIR_CW) set_frequency(1);
     else if  (result == DIR_CCW) set_frequency(-1);
     }
+#endif
 
 void tunegen() {
   si5351.set_freq((freq +  (interfreq * 1000ULL)) * 100ULL, SI5351_CLK0);
@@ -257,9 +280,13 @@ void setup() {
   si5351.output_enable(SI5351_CLK1, 0);
   si5351.output_enable(SI5351_CLK2,  0);
 
+ #ifdef ESP32DOIT
+  //TODO
+  #else
     PCICR |= (1 << PCIE2);
     PCMSK2 |= (1 << PCINT18) | (1 << PCINT19);
     sei();
+  #endif
 
   count = BAND_INIT;
   bandpresets();